Yes, Morneau is a baseball player, not a quarterback. But he got a "mild" concussion, and he missed eight months.

Alex was questionable all week, practicing in a black no-contact jersey, but the NFL concussion policy reads:

"Once removed for the duration of a practice or game, the player should not be considered for return-to-football activities until he is fully asymptomatic, both at rest and after exertion, has a normal neurological examination, normal neuropsychological testing, and has been cleared to return by both his team physician(s) and the independent neurological consultant."

We don't know about any remaining symptoms Alex is or isn't experiencing. But we do know that the independent neurologist said "No" to playing Monday night. And that "No" is based on medical tests, not opinion.

So what happens if Alex can't get clearance to return?

Colin Kaepernick will start, first of all. Kaepernick, San Francisco's 2011 second-round pick, has his supporters (of course he does—he's a backup quarterback). But the odds are that the San Francisco offense, already somewhat suspect, will not blossom under a player making his first seven starts.

Four of those seven games are road games against good teams: at St. Louis, at New Orleans, at New England and at Seattle. A fifth game is at home against Chicago, one of the premier defenses in the league and one that specializes in creating turnovers. In those five games, going 3-2 would be a major achievement with Smith under center.

With Kaepernick? Four hostile road crowds plus Chicago probably equals 1-4. On the other hand, home games against Arizona and Miami should be manageable for Kaepernick.

So if Alex Smith's concussion lingers, the Niners (6-2-1) are apt to lose the West to the Seahawks (who are 6-4, but four of their remaining six games are vs. Arizona, at Miami, at Buffalo in Toronto and vs. St. Louis).

Even if he's back in a week, once you have one concussion, it's easier to get another—and the next one takes longer to recover from.

San Francisco opened the season as a strong candidate to win the Super Bowl.